The present disclosure relates to a method for making articles, such as sputtering targets, containing Co, CoFe, CoNi, CoMn, CoFeX (X═B, C, Al), Fe, FeNi, and Ni. The articles may exhibit enhanced magnetic pass-through-flux (PTF) and low particulation during sputtering to shorten burn-in time for optimum operation. In some embodiments, preferably the sputtering targets exhibit a boron (B) content of greater than 15 at %, including 20 at % or more.
The marketplace for random access memory (RAM) is rapidly changing. Today, many electronic devices rely on magnetoresistive RAM (MRAM), based on field switching, as embedded memory. MRAM and spin-transfer torque RAM (STTRAM) will continue to replace static RAM (SRAM) and dynamic RAM (DRAM) in many electronic devices.
The core magnetic films forming magnetic tunnel junctions in MRAM and STTRAM are made of cobalt-iron-boron (CoFeB) alloys with high boron content. However, CoFeB alloys are extremely brittle and difficult to cast without cracking. High boron content CoFeB alloys are typically produced via sintering from powders, which makes it difficult to maintain low oxide/impurities levels and also high pass through flux (PTF).
It would be desirable to develop methods for casting crack-free alloy articles (e.g., sputtering targets) with high PTF, high purity, and low particulation at lower costs, amongst other characteristics.